Measuring health

Measuring Health using different health economics tools

1. MEASURING HEALTH Abdur Razzaque Sarker MHE (Health Economics), MSS (Economics) Health Economics and Financing Research, icddrb and PhD Fellow in Strathclyde University, UK Email: [email protected]

2. Why measuring health? For estimating health status of individual and population For assessing the impact of any health intervention For assessing equity in health across socioeconomic groups (based on income, education etc.), across countries etc. 2

3. Who should put “value” in health The individual? The society? 3

4. Kind of measurements Natural measurement: Healthy days, blood pressure level, healthy years, days without illness Quality adjusted measurement: Quality-adjusted life years (QALYs) and Disability-adjusted life years (DALYs) 4

5. Concept and measurement of QALYs The QALY as a composite measure of health status covering both dimensions – “quality” and “quantity”. QALYs 1.0 Time Weight Dead 10 year 0.8 QALYs = 10 × 1.0 = 10 QALYs = 10 × 0.8 = 8 5

6. QALYs without treatment: 0.5 year at 0.9 + 1 year at 0.7 = 1.15 QALYs with treatment: 0.25 year at 0.8 + 1 year at 0.9 + 0.5 year at 0.7 = 1.45 QALYs gained: 1.45-1.15=0.3 Application of QALYs 6

7. Some methods for estimating weight Rating scale Time trade-off Standard Gambling 7

8. Rating scale (Visual Analogue Scale – VAS) 8

9. Respondent is presented with a choice between living the rest of their life ( t ) in a given health state i (for example, on dialysis) or a shorter period of time ( x ) living in perfect health. Time x is varied until the respondent is indifferent between the two alternatives, at which point the required preference score for state i is x/t . Time-trade off (TTO) 1.0 Time Weight State i x Time (years) t If x = 6 years and t = 10 years Score for state i = 6/10=0.6 Dead 9

10. Respondent is given with two alternatives to choose Between. Alternative 1: Living at a health status ( i ), which is less than full health for t years Alternative 2: Having an intervention which can give the respondent full health with a certain probability or death. The probability where the respondent is indifferent between alternatives is the value of his or her health. Standard gambling 10

11. Probability (p) Full health Death Health i , years t Alternative 1 Alternative 2 Example: Selim is currently living (alternative 2) with disability and expected to have this condition 10 years before his death. He can have a surgical intervention (alternative 1) with a probability (p) of 75% that he will be fully cured and live rest of his life (10 years) at full health. At the same time there is a probability of (1-p) 25% that he can die during surgery. If Selim is indifferent in his choice between the two alternative, then his value of health is 0.75. 11

12. Instrument for measuring quality adjusted health EQ-5D SF-36/ SF-12 Health Utility Index Quality of well-being 12

13. EQ-5D Instrument ( EuroQol group) Total number of health states “245” (3 5 = 243 plus “unconscious” and “dead”) 13

14. Co-efficient for TTO tariffs Dimension Coefficient Constant 0.081 Mobility Level 2 0.069 Level 3 0.314 Self-care Level 2 0.104 Level 3 0.214 Usual activity Level 2 0.036 Level 3 0.094 Pain/discomfort Level 2 0.123 Level 3 0.386 Anxiety/depression Level 2 0.071 Level 3 0.236 N3 0.269 14

15. Example: Elma responded to his health as “11223” Mobility = No problem [1] Self-care = No problem [1] Usual activities = Some problems [2] Pain/discomfort = Moderate pain [2] Anxiety/depression = Extreme [3] EQ-5D weights Health Weight Full health 1.000 Constant - 0.081 Mobility - 0.000 Self-care - 0.000 Usual activities - 0.036 Pain/discomfort - 0.123 Anxiety/depression - 0.236 Constant (level 3/ N3) - 0.269 QALY-weight 0.255 15

16. THANKS 16 Email: [email protected]